Brian Kraskiewicz, an ecologist with the Forest Preserve District of DuPage County, talks about spotting a pileated woodpecker at St. James Farm Forest Preserve in Warrenville.

Brian Kraskiewicz, an ecologist with the Forest Preserve District of DuPage County, talks about spotting a pileated woodpecker at St. James Farm Forest Preserve in Warrenville. (Genevieve Bookwalter / Naperville Sun)

The pileated woodpecker, a crow-sized black bird with white stripes and a flaming red crest rarely seen in northeastern Illinois, is returning to the western Chicago suburbs with help from an unlikely source: the emerald ash borer.